Porous Organic Nanolayers for Coating of Solid-state Devices

Vidyala, Asghar Waseem, Iqbal

Description

Highly hydrophobic surfaces can have very low surface energy and such low surface energy biological interfaces can be obtained using fluorinated coatings on surfaces. Deposition of biocompatible organic films on solid-state surfaces is attained with techniques like plasma polymerization, biomineralization and chemical vapor deposition. All these require special equipment or harsh chemicals. This paper presents a simple vapor-phase approach to directly coat solid-state surfaces with biocompatible films without any harsh chemical or plasma treatment. Hydrophilic and hydrophobic monomers were used for reaction and deposition of nanolayer films. The monomers were characterized and showed a very consistent coating of 3D micropore structures. Results The coating showed nano-textured surface morphology which can aid cell growth and provide rich molecular functionalization. The surface properties of the obtained film were regulated by varying monomer concentrations, reaction time and the vacuum pressure in a simple reaction chamber. Films were characterized by contact angle analysis for surface energy and with profilometer to measure the thickness. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed the chemical composition of the coated films. Variations in the FTIR results with respect to different concentrations of monomers showed the chemical composition of the resulting films. Conclusion The presented approach of vapor-phase coating of solid-state structures is important and applicable in many areas of bio-nano interface development. The exposure of coatings to the solutions of different pH showed the stability of the coatings in chemical surroundings. The organic nanocoating of films can be used in bio-implants and many medical devices.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2011
• Nombre de lectures: 33
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

Vidyalaet al.Journal of Nanobiotechnology2011,9:18 http://www.jnanobiotechnology.com/content/9/1/18

R E S E A R C H

Porous Organic Nanolayers state Devices 1,2 2,3 2,3,4* Sri D Vidyala , Waseem Asghar and Samir M Iqbal

for

Coating

of

Open Access

Solid

Abstract Background:Highly hydrophobic surfaces can have very low surface energy and such low surface energy biological interfaces can be obtained using fluorinated coatings on surfaces. Deposition of biocompatible organic films on solidstate surfaces is attained with techniques like plasma polymerization, biomineralization and chemical vapor deposition. All these require special equipment or harsh chemicals. This paper presents a simple vaporphase approach to directly coat solidstate surfaces with biocompatible films without any harsh chemical or plasma treatment. Hydrophilic and hydrophobic monomers were used for reaction and deposition of nanolayer films. The monomers were characterized and showed a very consistent coating of 3D micropore structures. Results:The coating showed nanotextured surface morphology which can aid cell growth and provide rich molecular functionalization. The surface properties of the obtained film were regulated by varying monomer concentrations, reaction time and the vacuum pressure in a simple reaction chamber. Films were characterized by contact angle analysis for surface energy and with profilometer to measure the thickness. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed the chemical composition of the coated films. Variations in the FTIR results with respect to different concentrations of monomers showed the chemical composition of the resulting films. Conclusion:The presented approach of vaporphase coating of solidstate structures is important and applicable in many areas of bionano interface development. The exposure of coatings to the solutions of different pH showed the stability of the coatings in chemical surroundings. The organic nanocoating of films can be used in bioimplants and many medical devices.

Background The interface between biomedical and nanotechnology is an area of intense research. Integration of biomedical micro/nanoelectromechanical systems (BioMEMS/ NEMS) and materials offers tremendous potential to tackle medical problems in the areas of diagnostics, therapy, surgical implants and drug delivery [1]. In past few decades, fluorinated coatings have seen many appli cations in the fields of biochemistry and tissue engineer ing [24]. These coatings are used to attain low surface energy and corrosion resistance properties in nano and microstructured devices [5,6]. Organic composite films can be attained by many techniques, e.g. plasma poly merization, biomineralization, chemical vapor deposition

* Correspondence: [e-mail] 2 Nanotechnology Research and Teaching Facility, University of Texas at Arlington, Arlington, TX 76019, USA Full list of author information is available at the end of the article

(CVD) and self assembled monolayers (SAM) [713]. Two important goals of such coatings are biocompatibil ity and biostability; especially for the surfaces of medical implants. The biocompatibility and biostability can be achieved by modifying the surface characteristics of the substrates. Thus, surface modification of MEMS/NEMS structures has become one of the most important aspects of medicallyrelated devices. Structural stabilization of the coatings can be achieved from multiple covalent and hydrogen bonds using self organized silane films [14,15]. Fluorinated surfaces have been studied to modify the surface energy, reduce cell adhesion, increase protein adhesion, and also in the development of organicinorganic hybrid alloys [1618]. 3Aminopropyltrimethoxysilane (APTMS) and 1H,1H,2H,2HPerfluorooctyltrichlorosilane (PFTS) are nontoxic monomers commonly used to create fluorinated surface [7,19]. APTMS, being hydrophilic monomer, is

© 2011 Vidyala et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.